Why did the cambodian genocide happen?

OK,

The old system in Cambodia was kinda like a midieval feudal system. A few people rich and powerful. Everyone else working their a** off.

Then there was a Revolution. Because people were sick of it all. They killed the old leaders. The new leader after the revolution was Pol Pot. He was paranoid. And he wanted to form a totally socialist society where everyone was equal. And he exxagerated that completely.

Because now there were a lot of people who were more educated or richer than the average farmer and worker.

So the Red Khmer (Pol Pots troops) started killing everyone who was not ‘equal enough’ to fit in their world view. They also killed everyone who was objecting their ideas. And everyone who was trying to leave the country. And everyone who was not happy about the new system. And everyone who was strange and different. And everyone who did not work hard for the community (and was thus classfied a parasite to society). And everyone who lived in cities, because they’re not really famers and workers. And everyone else who was in any way not like they were supposed to be.

So after all, they killed a hell of a lot of folks only because they didn’t fit into the ideas of the perfect society. And they killed people to keep themselves in charge and to scare off any objectors.

That is - of course - not all there is to it. But you wanted it simple. Can you work with that?